reserve a,b,c,d for Real;
reserve r,s for Real;

theorem
  0 < b & b <= -a implies a/b <= -1
proof
  assume
A1: b>0;
  assume
A2: b <= -a;
  assume a/b>-1;
  then a/b*b>(-1)*b by A1,Lm13;
  then a>-b by A1,XCMPLX_1:87;
  hence thesis by A2,Th25;
end;
